Analytical techniques presently exist for the quantitative trace elemental analysis of most types of biological materials, provided sufficient sample is available. These techniques include atomic absorption spectrophotometry (AAS), inductively coupled plasma (ICP), atomic emission spectroscopy (AES) or mass spectrometry (MS). Electron probe minor elemental constituents. The electron probe technique is, however, incapable of detecting trace elements in those same specimens because of fundamental physical limitations. Consequently, there exists a need for a new quantitative trace elemental analysis technique capable of providing the detection limits of AAS or ICP-AES/MS at sample volumes approaching those of the electron microprobe. The Phase I research established the feasibility of employing high- performance secondary ion mass spectrometry (SIMS) to fulfill this role. However, before the technique can be usefully applied to microvolume analyses, the optimum procedures for sample collection and preparation, data acquisition and analysis of small amounts of material must be developed. the research proposed herein is designed to investigate these issues with the objective of developing relevant applications of this new technique to problems in biological materials analysis.